From 2b7db5b23df55e3a1ac0639494bea750d0797c9d Mon Sep 17 00:00:00 2001
From: bnewbold <bnewbold@eta.mit.edu>
Date: Wed, 11 Feb 2009 14:24:16 -0500
Subject: first pset work

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 ps01_grep/ps01_work.scm | 331 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 331 insertions(+)
 create mode 100644 ps01_grep/ps01_work.scm

(limited to 'ps01_grep/ps01_work.scm')

diff --git a/ps01_grep/ps01_work.scm b/ps01_grep/ps01_work.scm
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@@ -0,0 +1,331 @@
+;;; 6.945 Problem Set #1 - workfile
+;;; 02/10/2009
+;;; Bryan Newbold <bnewbold@mit.edu>
+
+(load "regexp.scm")
+
+
+(pp (r:grep (r:seq " "
+		   (r:repeat 3 5 (r:alt (r:quote "cat") (r:quote "dog")))
+		   (r:eol))
+	    "tests.txt"))
+
+;-------------------------------------------------------------------
+; 1.1: define r:* and r:+
+
+(define (r:+ pattern)
+  (r:repeat 1 #f pattern))
+
+(define (r:* pattern)
+  (r:repeat 0 #f pattern))
+
+(pp (r:grep (r:seq (r:quote "dog")
+		   (r:+ (r:quote "cat")))
+	    "tests.txt"))
+
+;("[09]. catdogcat" "[11]. dogdogcatdogdog" "[13]. acatdogdogcats")
+
+(pp (r:grep (r:seq (r:quote "cat")
+		   (r:+ (r:char-from (string->char-set "ogd")))
+		   (r:quote "cat"))
+	    "tests.txt"))
+
+;("[09]. catdogcat" "[13]. acatdogdogcats")
+
+(pp (r:grep (r:seq " "
+		   (r:+ (r:quote "cat"))
+		   (r:eol))
+	    "tests.txt"))
+; #f
+
+(pp (r:grep (r:* (r:quote "something that isn't there"))
+	    "tests.txt"))
+; matches all
+
+(pp (r:grep (r:repeat 2 3 (r:* (r:char-from (string->char-set "tca"))))
+	    "tests.txt"))
+; matches all: nothing repeated several times
+
+(pp (r:grep (r:seq (r:quote "dog")
+		   (r:+ (r:quote "cat"))
+		   (r:quote "dog"))
+	    "tests.txt"))
+
+;("[11]. dogdogcatdogdog")
+
+(pp (r:grep (r:seq (r:quote "dog")
+		   (r:* (r:quote "cat"))
+		   (r:quote "dog"))
+	    "tests.txt"))
+#|
+("[10]. catcatdogdog" "[11]. dogdogcatdogdog"
+                      "[12]. catcatcatdogdogdog"
+                      "[13]. acatdogdogcats"
+                      "[14]. ifacatdogdogs"
+                      "[15]. acatdogdogsme")
+|#
+
+;-------------------------------------------------------------------------
+; 1.2
+
+(define (r:repeat min max expr)
+  (if (not (exact-nonnegative-integer? min))
+      (error "Min must be non-negative integer:" min))
+  (if max
+      (begin
+	(if (not (exact-nonnegative-integer? max))
+	    (error "Max must be non-negative integer (or null):" max))
+	(if (not (<= min max))
+	    (error "Min not less than max:" min max))))
+  (cond 
+   ((not max) (r:seq expr (string-append "\\{" (number->string min) ",\\}")))
+   ((= max min) (r:seq expr (string-append "\\{" (number->string min) "\\}")))
+   (else (r:seq expr (string-append "\\{" 
+				    (number->string min) 
+				    "," 
+				    (number->string max) 
+				    "\\}")))))
+#| tests:
+(pp (r:grep (r:repeat 2 3 (r:quote "cat"))
+	    "tests.txt"))
+(pp (r:grep (r:repeat 2 #f (r:quote "cat"))
+	    "tests.txt"))
+(pp (r:grep (r:repeat 1 1 (r:quote "cat"))
+	    "tests.txt"))
+(pp (r:grep (r:repeat 4 3 (r:quote "cat"))
+	    "tests.txt"))
+(r:repeat 2 3 (r:quote "cat"))
+|#
+
+;---------------------------------------------------------------------------
+; 1.3
+
+(define (r:subexp . exprs)
+  (string-append "\\(" (apply string-append exprs) "\\)"))
+
+(define (r:seq . exprs)
+  (apply string-append exprs))
+
+(r:seq " " (r:subexp "sdf") "dddd")
+
+(define (r:repeat min max expr)
+  (if (not (exact-nonnegative-integer? min))
+      (error "Min must be non-negative integer:" min))
+  (if max
+      (begin
+	(if (not (exact-nonnegative-integer? max))
+	    (error "Max must be non-negative integer (or null):" max))
+	(if (not (<= min max))
+	    (error "Min not less than max:" min max))))
+  (cond 
+   ((not max) (r:seq (r:subexp expr) 
+		     (string-append "\\{" (number->string min) ",\\}")))
+   ((= max min) (r:seq (r:subexp expr) 
+		       (string-append "\\{" (number->string min) "\\}")))
+   (else (r:seq (r:subexp expr) 
+		(string-append "\\{" 
+			       (number->string min) 
+			       "," 
+			       (number->string max) 
+			       "\\}")))))
+
+(define (r:alt . exprs)
+  (if (pair? exprs)
+      (r:subexp (apply r:seq
+		       (cons (car exprs)
+			     (append-map (lambda (expr)
+					   (list "\\|" expr))
+					 (cdr exprs)))))
+      (r:seq)))
+
+(r:alt "first thing" "second thing")
+
+;----------------------------------------------------------------------------
+; 1.4
+
+(define (r:backref n)
+  (string-append "\\" (number->string n)))
+
+;----------------------------------------------------------------------------
+; 1.5
+
+; the following are only the expressions which had to be rewritten...
+
+(define (r-grep:seq . exprs)
+  (let ((choose-grep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) (car x))))))
+  (apply string-append (map choose-grep exprs))))
+
+(r-grep:seq "a" "b" '("grep" "egrep"))
+; abgrep
+
+(define (r-egrep:seq . exprs)
+  (let ((choose-egrep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) (cadr x))))))
+  (apply string-append (map choose-egrep exprs))))
+
+#| test:
+(r-grep:seq "a" "b" '("grep" "egrep"))
+; "abgrep"
+(r-egrep:seq "a" "b" '("grep" "egrep"))
+; "abegrep"
+|#
+
+(define (r:seq . exprs)
+  (cons (lambda () (apply r-grep:seq exprs)) 
+	(cons (lambda () (apply r-egrep:seq exprs)) '())))
+
+#| test:
+(r:seq "a" "b" '("grep" "egrep"))
+;Value: (#[compound-procedure 14] #[compound-procedure 15])
+((car (r:seq "a" "b" '("grep" "egrep"))))
+; "abgrep"
+((cadr (r:seq "a" "b" '("grep" "egrep"))))
+; "abegrep"
+|#
+
+(define (r-egrep:alt . exprs)
+  (let ((choose-egrep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) ((cadr x)))))))
+  (if (pair? exprs)
+      (apply r-egrep:seq
+	     (cons (choose-egrep (car exprs))
+		   (append-map (lambda (expr)
+				 (list "|" (choose-egrep expr)))
+			       (cdr exprs))))
+      (r-egrep:seq))))
+
+(define (r-grep:alt . exprs)
+  (let ((choose-grep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) ((car x)))))))
+    (if (pair? exprs)
+	(apply r-grep:seq
+	       (cons (choose-grep (car exprs))
+		     (append-map (lambda (expr)
+				   (list "\\|" (choose-grep expr)))
+				 (cdr exprs))))
+      (r-grep:seq))))
+
+(define (r:alt . exprs)
+  (cons (lambda () (apply r-grep:alt exprs)) 
+	(cons (lambda () (apply r-egrep:alt exprs)) '())))
+
+#| test:
+(r-egrep:alt "a" (r:dot) "c")
+;Value: "a|.|c"
+(r:alt "asdf" (r:dot))
+;Value: (#[compound-procedure 16] #[compound-procedure 17])
+((car (r:alt "asdf" (r:dot))))
+;Value: "asdf\\|."
+((cadr (r:alt "asdf" (r:dot))))
+;Value: "asdf|."
+|#
+
+(define (r-grep:repeat min max expr)
+  (let ((choose-grep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) ((car x)))))))
+    (if (not (exact-nonnegative-integer? min))
+	(error "Min must be non-negative integer:" min))
+    (if max
+	(begin
+	  (if (not (exact-nonnegative-integer? max))
+	      (error "Max must be non-negative integer (or null):" max))
+	  (if (not (<= min max))
+	      (error "Min not less than max:" min max))))
+    (cond 
+     ((not max) (r-grep:seq (r-grep:subexp (choose-grep expr)) 
+		       (string-append "\\{" (number->string min) ",\\}")))
+   ((= max min) (r-grep:seq (r-grep:subexp (choose-grep expr)) 
+		       (string-append "\\{" (number->string min) "\\}")))
+   (else (r-grep:seq (r-grep:subexp (choose-grep expr)) 
+		(string-append "\\{" 
+			       (number->string min) 
+			       "," 
+			       (number->string max) 
+			       "\\}"))))))
+
+
+(define (r-egrep:repeat min max expr)
+  (let ((choose-egrep (lambda (x)
+		      (cond
+		       ((string? x) x)
+		       ((list? x) ((cadr x)))))))
+    (if (not (exact-nonnegative-integer? min))
+	(error "Min must be non-negative integer:" min))
+    (if max
+	(begin
+	  (if (not (exact-nonnegative-integer? max))
+	      (error "Max must be non-negative integer (or null):" max))
+	  (if (not (<= min max))
+	      (error "Min not less than max:" min max))))
+    (cond 
+     ((not max) (r-egrep:seq (r-egrep:subexp (choose-egrep expr)) 
+		       (string-append "{" (number->string min) ",}")))
+   ((= max min) (r-egrep:seq (r-egrep:subexp (choose-egrep expr)) 
+		       (string-append "{" (number->string min) "}")))
+   (else (r-egrep:seq (r-egrep:subexp (choose-egrep expr)) 
+		(string-append "{" 
+			       (number->string min) 
+			       "," 
+			       (number->string max) 
+			       "}"))))))
+
+(define (r:repeat min max expr)
+  (cons (lambda () (r-grep:repeat min max expr)) 
+	(cons (lambda () (r-egrep:repeat min max expr)) '())))
+
+(define (r-grep:subexp . exprs)
+  (string-append "\\(" (apply string-append 
+			    (map (lambda (x)
+				   (cond
+				    ((string? x) x)
+				    ((pair? x) ((car x)))))
+				 exprs)) "\\)"))
+
+(define (r-egrep:subexp . exprs)
+  (string-append "(" (apply string-append 
+			    (map (lambda (x)
+				   (cond
+				    ((string? x) x)
+				    ((pair? x) ((cadr x)))))
+				 exprs)) ")"))
+
+(define (r:subexp . exprs)
+  (cons (lambda () (apply r-grep:subexp exprs)) 
+	(cons (lambda () (apply r-egrep:subexp exprs)) '())))
+
+#| test:
+(r:subexp "a" "b" (r:dot))
+;Value: (#[compound-procedure 25] #[compound-procedure 26])
+((cadr (r:subexp "a" "b" (r:dot))))
+;Value: "(ab.)"
+((car (r:subexp "a" "b" (r:dot))))
+;Value: "\\(ab.\\)"
+|#
+
+(define (r:grep expr filename)
+  (r:grep-like "grep" '() ((car expr)) filename))
+
+(define (r:egrep expr filename)
+  (if (eq? microcode-id/operating-system 'nt)
+      (r:grep-like "grep" '("-E") ((cadr expr)) filename)
+      (r:grep-like "egrep" '() ((cadr expr)) filename)))
+
+(pp (r:grep (r:seq (r:repeat 2 3 (r:quote "cat")) (r:+ (r:quote "dog")))
+	    "tests.txt"))
+
+
+
+
+
+
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